Surface-active substances with quaternary centers are divided roughly into amphoteric or zwitterionic surfactants on the one hand and cationic surfactants on the other hand. For both groups, there are countless examples in the market, such as, for example, the reaction products of fatty acid amidopropylamine with sodium chloroacetate (known under the INCI name Cocamidopropyl Betaine) or the alkylation products of triethanolamine fatty acid esters (known under the name ester quats). A common feature of these substances is their ability to attach to solid, especially negatively charged, surfaces, which is utilized, for example, for hand modifiers and hair-treatment compositions. Although the known products exhibit a performance which is in principle entirely satisfactory, there is still a desire for improved properties for a number of special applications. These include, in particular, the technically simple availability of concentrates with high storage stability.
Consequently, it was the object of the present invention to provide novel betaines or ester quats which, even at solids contents above 50% by weight, are flowable and pumpable, preferably have a Brookfield viscosity (20° C., spindle 1, 10 rpm) of less than 10 000 mPas and in particular less than 6 000 mPas. At the same time, the concentrates should neither gel nor change to a noteworthy degree with regard to their viscosity, even after storage at 40° C. for several weeks. Finally, it was desired to provide concentrates for various applications which are transparent even after prolonged storage under temperature. The demand for excellent biodegradability and dermatological compatibility represents a permanent requirement.